Prevalence and genetic characteristics of Saffold cardiovirus in China from 2009 to 2012

Zhang, Xiao-Ai; Lu, Qing-Bin; Wo, Ying; Zhao, Jin; Huang, Dou-Dou; Guo, Chen-Tao; Xu, Hong-Mei; Liu, En-Mei; Liu, Wei; Cao, Wu-Chun

Genetic characterization of SAFVs. A phylogenetic tree was constructed based on the VP1 nucleotide sequences of Saffold cardiovirus detected in clinical samples of 82 patients in the current study, and sequences downloaded from GenBank by maximum likelihood method using MEGA 6.0 (Figure 1) . A spatial pattern of the genetic clustering was identified for each genotype. For SAFV-1, four lineages were formed, and all the Chinese strains were grouped into one lineage (Figure 2A ). For the Chinese lineage, an obvious geographic-specific distribution was observed, with strains from three locations grouped separately into three sublineages. All the SAFV-1 cases from the current study were grouped into the Chongqing sublineage, regardless of the cohort group. In SAFV-2, five lineages were constructed, which included European, North American, Middle-Eastern, Japanese, and East Asian lineages ( Figure 2B ). The strains from the present study were grouped into East Asian lineage, which, however, diverged from those from Beijing or Thai strains. In SAFV-3, six lineages were formed depending on the geographical origin. The Chongqing strains in this study were classified into the Asian lineages, forming a sublineage that was distinct from the strains of other regions ( Figure 2C ). In SAFV-6, the strains from three locations were classified into three clusters. The Chongqing strains formed a separate cluster, which is different from those of Japanese and Pakistani strains ( Figure 2D ).